Abstract: Two sets of home-made laser ablation ionization time-of-flight mass spectrometers were introduced. These instruments compared to other solid sample direct analysis methods have many merits：easy pre-sampling, samples quick changing (only several minutes), ability for micro-space analysis, spectrum with few interference and very low absolute determination limit （10¹⁵g grade）. The best mass resolutions of these two mass spectrometers can achieve 7 000 and 4 000 (FWHM) respectively. The impacts of different sample introduction method and ion transmission system on instrument performances were also analyzed comparatively in this article.